Modern motor vehicles, particularly hybrid vehicles, may utilize a sealed fuel system as a strategy to limit evaporative emissions. Once sealed, the fuel system is subject to internal pressure changes from changes in temperature. If the vehicle user removes the fuel cap while the system is pressurized, fuel vapor escapes into the atmosphere.
The prior art has proposed a system in which the vehicle user presses a button when the vehicle is to be refueled. Pressing the button initiates a process in which the fuel tank is depressurized by venting the fuel vapor pressure through a hydrocarbon capturing system so that fuel vapor is not vented into the atmosphere.
The prior art has also proposed that a latch be installed on the fuel filler door, and this latch will not release until the hydrocarbon capturing system has completed its process of depressurizing the fuel tank. After the fuel vapor pressure is relieved and reaches the same pressure as the atmosphere, the fuel filler door is unlocked, so that the user can open the fuel filler door and unscrew the fuel cap.